Method and apparatus for producing molded tubular objects from polymer concrete

ABSTRACT

A method and apparatus for producing tubular molded products from molding material includes a mold casing and a mold core having a common longitudinal central axis which is vertically disposed. The mold casing and mold core are spaced from one another to define a molding space therebetween. A supply device supplies molding material from above the molding space into the molding space. Treatment apparatus is disposed at treatment zones on the mold core for treating the molding material in the molding space, the treatment including treating the molding material by shaking the molding material or treating the molding material by heating the molding material, or both. The mold casing has an axial length which is less than an axial length of the molded product, to be produced and apparatus is provided for lowering a lower end of the column of molding material in the molding space in a direction parallel to the central axis from an initial position to a lowered position which enables production of a molded product of a desired longitudinal length.

BACKGROUND OF THE INVENTION

The invention relates to a method and an apparatus for producing pipesor similar tubular molded objects from polymer concrete. The inventionfurthermore relates to a polymer concrete socket pipe.

In practice, for the production of pipes from polymer concrete, moldingequipment is used, which consists of a mold core and a mold casing,which together form the boundary of a molding space. The molding spaceof the molding equipment, the main axis of which is aligned vertically,is filled with a mineral casting composition by means of fillingequipment and this mineral casting composition is subsequently shaken asa whole. Sometime after the end of the shaking process, the mineralcasting composition, which is at ambient temperature, commences to cure.After the curing process is largely concluded, the molding equipmentcasing is removed from the molded object. Since the pipe shrinks as itcures and, during the slow course of the curing process, the casingcannot be removed from the pipe before considerable shrinkage occurs, asleeve-like compensating body, which then lines the finished pipe as aliner, must be placed on the mold core.

In the case of a method of an older proposal (P 43 39 118.4), the moldedobject is built up sectionwise along its central axis by fillingconsecutive longitudinal sections of the molding space of the moldingequipment with mineral casting composition and shaking the mineralcasting composition in the filling region and is cured sectionallyphase-offset in the same direction. For this purpose, the moldingequipment has a mold casing of superimposed, transposable casingsegments, the segment parts of which in each case can be moved apartfrom an annular, closed operating position into nonoperative positionand transposed in this position. The mold core is divided into axiallylimited sections, which form different treatment zones, it beingpossible to move the mold casing and mold core relative to one anotherin the axial direction during the production of a molded object.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a method and an apparatusfor producing molded objects, particularly a socket pipe, from polymerconcrete. The method and apparatus are to enable tubular molded objectsto be produced from polymer concrete with little operational andstructural expense.

The invention enables pipes and tubular molded objects to be producedwith a continuous or quasi continuous formation of the molded object ina molding space, which is stationary at least in the main part and whichis traversed by the column of mineral casting composition. At the sametime, the column of material is molded, solidified and cured. Thestructural expense of the molding equipment is exceedingly low, so thatadvantageous operating processes as well as simple retrofittingpossibilities arise for the production of molded objects of differentdimensions.

Further advantages and details of the invention arise out of thefollowing description and the drawing, in which two examples ofinventive molding equipment are shown diagrammatically.

FIG. 1 shows a side view of a first embodiment of the inventive moldingequipment, partially in section, in a basic position before the start ofthe manufacturing process,

FIG. 2 shows a side view, half in section, similar to that of FIG. 1 toillustrate parts of an initial phase of the production of the moldedbody,

FIG. 3 shows a side view similar to that of FIG. 1 to illustrate theparts at the conclusion of the manufacturing process of a molded object,

FIG. 4 shows a partial, truncated, longitudinal section through a lengthregion of the upper part of the mold casing,

FIG. 5 shows a section along the line V—V of FIG. 4,

FIG. 6 shows a partial, truncated, longitudinal section, similar to thatof FIG. 4, through the lower end of the molding space,

FIG. 7 shows a diagrammatic plan view of the closing part with moldsegments as inner mold for the socket part,

FIG. 8 shows a representation of a further embodiment of the inventivemolding equipment,

FIG. 9 shows a sectional enlargement of FIG. 8 with a closing body in astarting position at the commencement of the manufacturing process,

FIG. 10 shows a representation similar to that of FIG. 8 to illustratethe molding equipment in a later phase of the operation,

FIG. 11 shows an enlarged sectional representation of the moldingequipment of FIG. 8 to illustrate positions of the molding body in theprocess of formation while severing the film curtains, during theintroduction of the intermediate supporting elements and afterassumption of the support by these,

FIG. 12 shows a representation similar to that of FIG. 11 to illustratepositions of the molded object in the process of formation inconsecutive phases of the continuous production process,

FIGS. 13 and 14 show enlarged sectional representations of the moldingequipment of FIG. 8 for a more detailed diagrammatic representation ofthe interior tool of the film-severing equipment in two mutuallyorthogonal viewing directions,

FIGS. 15 and 16 are representations similar to those of FIGS. 13 and 14to illustrate the exterior tool of the film-severing equipment and itssupport as well as the support of the intermediate supporting elements,

FIG. 17 shows a section along the line XVII—XVII of FIG. 15,

FIG. 18 shows a representation similar to that of FIG. 12 to illustratethe position of a finished molded object directly before it isdischarged from the molding equipment,

FIG. 19 shows a diagrammatic plan view of discharging equipment forfinished molded bodies, and

FIGS. 20 to 22 show truncated cross-sectional representations of socketpipes in a two-part construction.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The apparatus, shown in FIGS. 1 to 7, is intended for the production ofsocket pipes M and comprises, in particular, molding equipment 1 with avertical, longitudinal central axis 2, which equipment has a mold core 3and a mold casing 4, as well as filling equipment, 5 for supplying amineral casting composition into a molding space 6, formed between themold core 3 and the mold casing 4.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the vertical direction, the mold casing 4 comprises a stationary part7, the inner wall 8 of which forms the outside boundary of the moldingspace 6 and preferably is constructed cylindrically. For maintenancepurposes, it may be possible to divide or dismantle part 7. Underoperating conditions, however, part 7 forms a closed structural unit.The axial length of part 7 corresponds to a fraction of the pipe to beproduced and may, for example, have the dimensions of 120 cm.

In the case of the example shown, part 7 forms the upper part of themold casing 4 which, in a plane running perpendicularly to thelongitudinal central axis 2, is divided into two parts 7, 9, of whichthe lower part 9 forms the boundary of the molding space 6 in the regionof the socket part of a socket pipe M that is to be produced and, in theaxial length, may be limited essentially to the axial length of thesocket region. In its axially extending plane, the lower part 9 isdivided into two half parts 10, 11, which can be moved by means ofdriving mechanisms 10 a, 11 a along diagrammatically indicated guides12, 13 in opposite directions, horizontally, from a closed operatingposition (FIGS. 2 and 3) into an opened demolding position (FIG. 1).

For closing off the molding space 6 at the bottom, a closing part 14 isprovided, which can be lowered from an upper starting position (FIGS. 1and 2) into a lower end position by a distance, which correspondsessentially to the nominal length of a molded object to be produced,which in this case is a socket pipe M. In particular, the closing part14 comprises a ring-shaped supporting panel 15 and an inner mold 16 ofthe socket part, which is supported on the supporting panel 15.

The lower part 9 of the mold casing 4 is supported on the supportingpanel 15 of the closing part 14 and can be lowered together with theclosing part 14 from the upper starting position of the latter into thelower end position of the latter, as is illustrated in FIG. 3. In thelower end position of the closing part 14, the half parts 10, 11 of thelower part 9 of the mold casing 4 can be transferred to the finaldemolding position, as is indicated by the arrows 17, 18, and can beraised in this demolding position together with the closing part 14 intoan intermediate position (FIG. 1) at the level of their operatingposition immediately below the upper part 7, as indicated by arrows 19,20. From the intermediate position, the half parts 10, 11 can then bemoved horizontally in opposite directions inwards into the operatingposition (FIG. 2) (Arrows 21, 22). For this purpose, the closing part 14is supported on a lifting table 23, which can be shifted along thevertical guides 24, which can be constructed as threaded spindles andmay be driven by means of driving mechanisms indicated diagrammaticallyat 25.

Preferably, the parts 3, 4, 14 of the molding equipment 1 are mounted sothat they can be swiveled as a whole alternately about the longitudinalcentral axis 2. The swiveling angle may, for example, amount to about300°. The outlet 5 a of the filling equipment 5 is stationary anddischarges into the region above the molding space 6, which is opentowards the top. This ensures that the molding space 6 is filleduniformly with the mineral casting composition.

Instead of this, it is, however, also conceivable to move the fillingequipment 5 or its outlet 5 a, when the latter is formed, for example,by a hose, on a circular path in such a manner, that the outlet 5 acircles above the molding space 6 about the longitudinal central axis 2with a sector angle of about 300°.

To insure pivotability about the longitudinal central axis 2, the upperpart 7 of the mold casing 4 is supported over a mounting device 5 a on astationary, annular supporting table 27 and the closing part 14 of themold casing with its supporting panel 15 is supported over a mountingdevice 28 on the lifting table 23, so that the parts 7 or 9, 14 can beswiveled basically independently about the longitudinal, central axis 2.Diagrammatically shown driving mechanisms 3 a, 7 a, 9 a, however, ensurethat the parts 3, 7, 9 and 14 experience synchronous, alternatingswiveling. To ensure the swiveling motion of the mold core 3, the latteris supported at a central guiding element 29, which is carried in theregion of its upper end by a mounting device 30.

Groups of supply rolls 31, 32 for film strips, which form the moldcurtains 33, 34 lining the molding space 6 on the inside and theoutside, are assigned to the mold core 3 and the upper part 7 of themold casing 4. The supply rolls 31, assigned to the mold core 3, aremounted on a supporting frame 35, which is supported at a centralguiding element 29 for the mold core 3 and participates accordingly inthe alternating swiveling motion of the central guiding element 29 withthe mold core 3. The supply rolls 32, assigned to the upper part 7 ofthe mold casing 4, are mounted at a supporting frame 36, which issupported at an upper part 7, and participate accordingly in thealternating swiveling motion of the upper part 7 of the mold casing 4.

The film strips, which run off from the supply rolls and preferablyconsist of polyester, may, for example, have a width of 10 cm andoverlap in the film curtain 33 or 34 by, for example, about 10 mm. Afteronset of the mutual overlapping and before they enter the molding space6, the strips can be connected with one another at the edges, forexample by gluing or sealing the edges. Instead of this, it is alsopossible to form the film curtains in each case from only two filmstrips or to use a tubular film and to take this tubular film from astorage bin containing tubular film folded in zigzag fashion.

Instead of lining the inside and the outside of the molding space 6 witha film or also in addition to such lining, it is possible to use alubricant, which can emerge, for example, from delivery openings in theupper edge region of the inner wall of the upper part 7 and fromdelivery openings in the mold core 3 in a region close to the upper endof the molding space 6 and can coat the axial boundary surface of themolding space 6 with a film in such a manner, that the mineral materialcomposition or the film pass by the boundary surfaces without directcontact. The lubricant can be one which, upon complete curing of themineral casting composition, becomes a permanent component of thesurface or fulfills strictly a lubricating function, when it is used inaddition to a film.

In order to fix film curtains 33 and 34 during and between operationalprocesses, annular suction adhesion regions 37, 38, 39 and 40 areprovided in each case in the region of the lower edge of the inner wall8 of the upper part 7 of the mold core 3, of the upper edge of the innerwall of the lower part 9 of the mold core 3, of the lower edge of theouter wall of the mold core 3 and of the rear wall of the inner mold 16of the socket part of the closing part 14 facing the mold core 3. Thesuction adhesion regions 37, 38, 39, 40 are formed by chambers 41, whichcan be connected to a vacuum source and evacuated and are connected oversuction openings 42 with the molding space 6.

For severing the film curtains 33, 34 in a plane, which extends at aspecified distance below the underside of the upper part 7 of the moldcasing 4 and above the upper end of the finished molded object Mtransversely to the longitudinal central axis 2, film-severing equipment(FIG. 3) is provided, which is indicated diagrammatically at 43 and canhave a heatable severing wire, for example, as a severing element.

At its surfaces facing the molding space 6, the inner mold 16 of thesocket part of the closing part 14 can have a coating 44, which yieldsunder shrinkage pressure. This coating 44 enables the socket part of thesocket pipe M to shrink during the presence of the part 16. In additionto or instead of this, the inner mold 16 of the annular socket part mayalso be formed by a number of mold segments 45, which are supported fromtheir operating position radially inwards on the supporting panel 15 andcan shift radially inwards, for example, against the action of a spring,if they are acted upon by the shrinkage pressure of the curing mineralmaterial composition. In the supporting panel 15, preferably drivingmechanisms 16 a are provided, by means of which the mold segments 45 ofthe inner mold 16 of the socket part can be moved between theiroperating position and an inwardly shifted demolding position, in whichthey are disengaged from the socket part of the socket pipe M, even whenthe latter shrinks. In order to offer an essentially closed boundarysurface in the operating position and nevertheless to make possible theshifting from the operating position into the demolding position,relatively wide mold parting lines, in which an elastically compressiblesealing element 45′ is provided, may be provided between the moldsegments 45, of which four are preferably provided.

The mold casing 4 can be heated over the whole height of the moldingspace 6 and, for this purpose, has heating means, which carry out theheating for example, by electrical means, in the walls of its upper andits lower parts 7, 9. The heating can also be accomplished by a liquidor gaseous heating medium, which can be passed through heating ducts 46in the upper and lower parts 7, 9 of the mold casing 4. Appropriateheating means are also provided in the mold core 3, namely in the regionof a heating zone, which can extend practically over the height of thewhole of the molding space 6, as in the case of the mold casing 4.Instead of this, it is also possible to provide a heating zone in themold core 3, which heating zone, in the operating position of the moldcore, commences only at a distance below the upper end of the moldingspace 6 and extends as far as the lower end of the molding space 6.

The mold casing 4 and/or the mold core 3 can have a heating zone 48,which comprises microwave generators 47 as heat generators. Themicrowave heating zone 48 preferably is assigned to the mold casing 4 inthe region of its upper part 7 and, for the heating, is providedadditionally with heating means of the previously mentioned typealthough, in principle, heating exclusively by electromagneticmicrowaves is also conceivable.

The mold core 3 has a shaking zone which, at the start of amanufacturing process, initially consolidates the mineral castingcomposition in the lower part of the molding space adjoining the lowerend of the molding space 6 and then, as the level of the mineral castingcomposition in the molding space 6 rises, is intended to consolidate themineral casting composition also in upwardly adjoining regions of themolding space and, finally, in that region of the molding space 6, whichadjoins the upper end of the molding space 6. This can be brought aboutin that, in the mold core 3, an axially limited shaking zone is formed,which is level with the lower region of the molding space 6 at the startof the manufacturing process and then, by pulling up the mold core 3, ismoved into an upper end position, which adjoins the upper end of themolding space 6 and in which it then remains stationary during thefurther manufacturing process.

Instead of that, the shaking zone can also extend over the whole heightof the molding space 6 and be formed by axially limited partial shakingzones 50, 51, 52, which are disposed one above the other and havevibrators 55, which can be switched on and off independently of oneanother. The partial shaking zones 50, 51, 52 can, at the same time,each embrace a separate mold core pipe section which, while retaining ajoint 54, bridged by an elastic seal, is supported independently at aninternal support of the mold core 3 and, in each case, carries its ownvibrator 55. The mold core 3 shown has three partial shaking zones 50,51, 52, which are separated by joints 54 from one another and from theparts of the mold core 3 adjoining above and below. Accordingly, firstthe partial shaking zone 50, then the partial shaking zone 51 andfinally the partial shaking zone 52 can be activated by switching on thevibrator and the active region of the shaking zones can thus be extendedin steps from the bottom to the top over the full height of the moldingspace 6. If the vibrators in the partial shaking zone 50 are switchedoff after the vibrators in the partial shaking zone 51 are switched onand, if the vibrators in the partial shaking zone 51 are switched offafter the vibrators in the partial shaking zone 52 are switched on, thenthe active region of the shaking zone can also be shifted axially fromthe bottom to the top.

For producing a film object in the form of a socket pipe M, the halfparts 10, 11 of the lower part 9 of the mold casing 4, starting out fromthe position of the parts in FIG. 1, are initially transferred by amovement in the direction of the arrows 21, 22 into their operatingposition, in which the suction adhesion region 38 comes to lie oppositeto the lower end of the film curtain 34 and fixes this by applying avacuum.

After that, the mold core 3 is lowered into a position, in which itssuction adhesion region 39 lies opposite and is aligned with the suctionadhesion region 40 of the closing part 14. In this position of theparts, the suction adhesion region 39 is deactivated and the suctionadhesion region 40 activated, so that the film curtain 33 is loosenedfrom the lower end of the mold core 3 and fixed to the closing part 14.

After this preparation of the molding equipment for the productionoperation, the parts of the equipment are in the position of FIG. 2, inwhich the molding equipment 1 is then caused to swivel alternately aboutthe longitudinal central axis 2. With or after the onset of thisalternating oscillatory movement, the filling equipment 5 is set inoperation and mineral casting composition is filled over the outlet 26into the molding space 6. At this point in time, the heating zones ofthe mold casing 4 and of the mold core 3 are operating with the resultthat the boundary walls of the molding space 6 have their specifiedoperating temperature, for example, of the order of 70-100°.

As the filling of the molding space 6 commences, the lowest partialshaking zone 50 of the mold core 3 is started up and the partial shakingzones 51 and 52 are switched on as soon as the level in each casereaches their lower end. With the switching on of the partial shakingzone 51, the shaking in the partial shaking zone 50 can be switched offand, with the switching on of the partial shaking zone 52, the shakingin the partial shaking zone 51 can also be switched off, so that shakingtakes place now only in the region of the partial shaking zone 52.

When the nominal upper level in the molding space 6 is reached, thefurther supply of mineral casting composition, to begin with, isinterrupted until, as a result of the heating of the mineral castingcomposition, the curing process commences in this composition in theregion of the lower part 9 and in the lower region of the upper part 7and leads to a first solidification of the mineral casting composition,which makes it possible to commence now with the lowering of the closingpart 14 along with the lower part 9 along the guides 24. With the onsetof the lowering process, the column of material in the molding space 6as a whole commences a downward motion, which is produced by gravity andoptionally supported by the pulling action on the film curtains 33, 34and, with the start of which, the supplying of mineral castingcomposition by the filling equipment 5 is resumed and metered in such amanner, that the level in the molding space 6 is maintained essentiallyconstant at the scheduled height. As the lowering of the material columnin the molding space 6 commences, the heating zone 48 additionally isactivated in order to intensify the transfer of heat to the materialcolumn in motion and to ensure that, in the mineral casting compositioncontinuously moving downwards in the molding space 6 between the upperpart 7 and the mold core 3, a curing process is initiated, whichgenerates in the mineral casting composition, emerging from the upperpart 7, already such a strength that the necessary shape maintenance ofthe molded object M is assured during the further downwards motion.

In general, it is possible to control the shaking and heating whilecontinuously filling the molding space and continuously lowering thecolumn of material in such a manner, that the formation of the molded Mobject proceeds continually. It is, however, also conceivable to formthe molded object M in steps. For example, at the start of theproduction process, the molding space 6 can be filled very rapidly up toa nominal height and the filling and shaking can be followed by a phase,in which the mineral material composition is merely heated. This canthen be followed by a relatively rapid lowering process of the column ofmaterial with appropriate maintenance of the nominal state in themolding space 6, until approximately the whole of the preconsolidatedpart of the column of material is moved out of the molding space in theupper part 7. At this time, the further lowering motion of the parts 9,14 is interrupted until the column of material, which is in the moldingspace in the upper part 7 at this time, has acquired the preliminarysolidification, required so that it can be discharged from the moldingspace 6, as a result of the curing process that has been initiated.Subsequently, in a rapid lowering motion, this part of the column ofmaterial is once again essentially discharged from the molding space 6which, while stopped, is filled with more material composition for thenext discharging process, until the production of the molded object isconcluded.

The question of moving the column of material continuously through themolding space 6 or moving the mineral material compositionintermittently depends essentially on the formulation of the mineralcasting composition and on the therefrom resulting temperature, at whichthe curing process is initiated, as well as on the pot life and thecuring rate. Preferably, a mineral casting composition is used, whichoffers an initiating temperature, which is raised above ambienttemperature and preferably falls in the range of about 50 to 90° andadvantageously between 60 and 70° due to the addition of a curing agent,and which contains a curing accelerator, such as a cobalt accelerator,which shortens the curing process.

If, in the course of the production process conducted in the mannerdescribed above, the column of material has reached a lengthcorresponding to the nominal length of the pipe that is to be produced,the further supply of mineral material composition is terminated byswitching off the filling equipment 5 and the handling process iscontinued until the parts essentially have reached the positionillustrated in FIG. 3, in which the closing part 14 and the lower part 9are in their final, lower position. At the same time, the upper end ofthe socket pipe M produced is at a specified distance below the upperpart 7.

For demolding the socket pipe M, the mold core 3 is first moved upwardssome distance, until the lower end of the mold core 3 is slightly abovethe severing plane, which is defined by the equipment 43 and in whichthe equipment 43 subsequently severs the film curtains 33, 34.Previously, the film curtains 33, 34 were fixed by activating thesuction adhesion region 39 of the mold core 3 and the suction adhesionregion 37 of the upper part 7. Thereupon, the half parts 10, 11 aremoved apart horizontally as indicated by the arrows 17, 18 along theguides 12, 13 into the demolding position. At the same time, the moldsegments of the inner mold 16 of the socket part are shifted inwardsinto their demolding position by means of the driving mechanism 45, sothat the socket pipe M, which is still surrounded on the outside andinside by film, can be removed by means of hoisting equipment and takenaway for further treatments. Subsequently, the lifting table 23 isshifted upward along the guides 24 in the direction of the arrows 19,20, until the position of FIG. 1 is reached, starting out from which anew production process can now be commenced.

When pipes are produced with a cross section, which remains the sameover the whole length, it is possible to do without the lower part 9 andthe closing part 14 can consist essentially of the supporting panel 15alone. The process can be controlled automatically, programmed on thebasis of measurement data, such as the outside temperature of the columnof material at a level equal to that of the lower end of the upper part7, the weight or the volume of the mineral material compositionsupplied, the level of material in the molding space 6, the position ofthe closing part on its way to the lower end position, etc. Depending onthe length and diameter of the pipes to be produced and on thecomposition of the mineral casting composition, cycle times of the orderof 2 to 4 minutes can be attained.

The second embodiment of inventive mold equipment, illustrated in FIGS.8 to 19, corresponds largely with that of FIGS. 1 to 7 and identicalparts have been given the same reference numbers. Contrary to the moldequipment of FIGS. 1 to 7, the second embodiment of FIGS. 8 to 19 has amold casing 4, which consists only of the stationary, closed upper part7. The lower part 9 is not required, since pipes with a constant crosssection or with one or two spigots or ends of a similar nature are to beproduced with the second embodiment, for which changes in shape liewithin the cylindrical contour of the tubular body.

The closing part 14′ of the second embodiment has a basically differentconstruction. Admittedly, it also encompasses the supporting panel 15.Primarily, however, it comprises a separator 60, which can be insertedfrom above into the molding space 6 between the mold casing 4 and themold core 3 and forms the lower boundary of the molding space 6. As canbe seen, for example, in FIGS. 9 and 17, the separator 60 is constructedas an annular part, which molds at least one adjacent end 61 of a moldedbody R, which is to be formed, into a spigot. For this purpose, theseparator 60 is provided with an external annular flange 62, whichextends upwards from the upper side 63 of the separator 60 at the outerperiphery and, with that, parallel to the adjacent inner wall 8 of themold casing 4. In the drawing, the annular flange 62 is reproduced onlydiagrammatically. The exact conformation of its shape is determined bythe exterior shape of the pipe end, which is to be formed. If moldedbodies R are to be formed with two spigots, the separator 60 can beprovided additionally with a ring shoulder (not shown), corresponding toring shoulder 62 and extending downward.

The separator 60 is provided on the inside and outside with a peripheralindentation 64 or 65 for engagement by film severing elements, whichwill be dealt with in greater detail below. The separator 60 furthermorehas holding pockets 66, which are open to the outside and into whichintermediate supporting elements 67, which will be described in greaterdetail below and can be provided with a vertically aligned central slot68, can be introduced. As a result of the slots 68, the intermediatesupporting elements 67 can be introduced into two holding pockets 66each and accommodate in their slot 68 a partition 69 between adjacentholding pockets 66.

As can be inferred from FIG. 17, the separator 60 is divided in thevertical direction into several segments 70 (four in the Example shown),which make it possible to assemble the separator 60, for example, withthe help of feeding equipment, the details of which are not shown, in aregion immediately above the filling opening of the molding space 6 bymoving the segments 70 together and then introducing the assembledseparator 60 into the molding space 6 from above. Due to the segmentedconstruction, the separator 60 can be detached at the end of theformation of the molded object from the molded object R by pulling offthe segment 70 radially.

Below the mold casing 4 and the mold core 3, film-severing equipment 75with an inner and an outer severing tool 76 and 77 respectively isprovided and illustrated in some of the Figures of the drawing only by aline representing the severing plane. However, as shown particularly inFIGS. 13 to 16, each severing tool 76, 77 is provided with a number ofradially directed cutting knives 78, which can be moved in each case bymeans of a diagrammatically illustrated pressure medium cylinder 79,from the neutral position shown radially (outwards or inwards) into anoperating position, in which they in each case reach through thecylindrical surface of the film curtains 33 and 34 and protrude into theindentations 64 and 65 respectively of a separator 60, the horizontalcentral plane of which, when the film-severing equipment 75 is actuated,is level with the severing plane of the film-severing equipment 75.

In the operating position of the cutting knives 78, the severing tools76, 77 can be swiveled alternatingly about their respective centralaxis, which coincides with the longitudinal central axis 2 of themolding equipment 1. The swiveling angle is selected so that the cuttingknives 78 together pass through an uninterrupted circular arc.

The inner severing tool 76 is fastened to the underside of the mold core3 and rotatably supported in a bearing part 80 and can be swiveledalternatingly by means of a driving mechanism 81. The outer severingtool 77 comprises an annular support 82, which is guided between upperand lower guide rolls 83, 84 and can be swiveled alternately by means ofa pressure medium driving mechanism 85.

The guide rolls 83, 84 are supported on the upper side of an outersupporting ring 86, which is suspended from the underside of the moldcasing 4. For this purpose, the outer supporting ring 86 is movablysupported at the guides 87 parallel to the longitudinal central axis 2of the mold equipment 1 and can be moved by means of a driving mechanism88 between an upper end position and a lower end position. In the caseof a particularly simple embodiment, the guides 87 are constructed asthreaded spindles, which reach through counterthreads in the outersupporting ring 86 and can be driven uniformly to one another by meansof synchronous motors 88, so that the outer supporting ring 86experiences a precisely parallel shift.

At its underside, the outer supporting ring 86 supports the intermediateholding elements 67, which in each case can be moved by means of apressure medium driving mechanism 89 from a neutral position radiallyinwards into engagement with the holding pockets 66 of a separator 60.In this way, the intermediate holding elements 67, of which, forexample, four, distributed over the periphery are provided, can be movedup and down for purposes, which will still be discussed further below.

At its upper side, the supporting panel 15 carries fastening jaws 90,which can be moved in each case by means of a pressure medium drivingmechanism 91 from a neutral position radially inwards into engagementwith the lower end of a molded body R supported on the supporting panel15 or with the separator 60 surrounding this end, in order to secure theend of the molded body on the supporting panel 15.

For discharging finished molded bodies R from the molding equipment 1,discharging equipment 92, which is located laterally next to the moldingequipment 1 in the neutral position, is provided at a height between thesupporting panel 15 in its lower end position and the outer supportingring 86. The discharging equipment 92 has two groups of suction grippers93, 94, which are disposed mutually above one another, in the initialgripping position lie diametrically opposite to one another and to themolded object R and can be moved by means of a pressure medium drivingmechanism 95 from a neutral position radially inwards in oppositedirections against the molded object R and can be acted upon with avacuum by means of a pressure medium source, which is not shown.

The grippers 93, 94 are supported at a frame 96, which can be movedhorizontally and makes it possible to bring a finished molded body R,which has been taken hold of, from its position in the molding equipment1 to a storage area, which can be formed, for example, by a furtherprocessing station, a refrigerated room or the like. The movement of theframe 96 can be brought about, for example, with the help of threadedspindles 97, which can be driven by driving motors that are not shown.

For starting up the apparatus, the film curtains 33, 34 are suspended ina molding space 6 and in the molding space 6 and, at the same time, atubular spacer 98, which is supported on the supporting panel 15 andsecured on this with the help of the fastening jaw 90, is introducedfrom below between the film curtains 33, 34. The separator is thenintroduced from above into the molding space 6 between the film curtains33, 34 and placed on the upper end of the spacer 98.

At the start of the process for producing a molded object R, the firstseparator 60 is in a position relatively closely beneath a specifiedupper nominal height for the mineral casting composition in the moldingspace 6, so that, after the introduction of the mineral castingcomposition by means of the filling equipment 5 is commenced, thespecified nominal height is soon reached. At the time at which thecharging of the filling space 6 with mineral casting composition iscommenced, the parts 3, 4 (including the parts connected with these) arein alternating swinging motion, so that the mineral casting compositionis distributed rapidly and uniformly in the molding space 6.Furthermore, at this time, the shaking zone 52 of the mold core 3,adjoining the upper end of the molding space 6, is also already inoperation, so that, as soon as the filling of the mineral castingcomposition is commenced, this composition is shaken in the moldingspace 6.

When the specified filling level is reached, the lifting table 23 ismoved downward. This downward motion is coordinated by the fillingequipment 5 with the mineral casting composition supplied in such amanner, that the nominal height is constantly maintained. Above theseparator 60, which is lowered with lifting table 23, a column ofmaterial is accordingly built up progressively and preferablycontinuously in the molding space 6 and passes first through the shakingzone 52 and then through a downwardly adjoining heating zone, in whichit is exposed to heating, preferably from inside as well as fromoutside. In the course of the heating, the curing process is initiated.As a result, in a region above the outlet plane of the molding space 6,the molded body R, which is being formed, in each cases reaches a degreeof curing, which provides the emerging end of the molded body with sucha strength (for example, 20% to 25% of the final strength), thatundesired shape changes are excluded.

As soon as the separator 60 reaches the region of action of thefilm-severing equipment 75, a downward motion is imparted to the outersupporting ring 86, which corresponds to the downward motion of theseparator 60, so that there is no relative axial motion between theseparator 60 and the cutting knives 78 of the film-severing equipment 75during the subsequent severing of the film curtains 33, 34. As soon asthe film severing process is concluded and the knives 78 have beenreturned to their neutral position, the outer supporting ring 86 returnsto its upper end position, in which at this time the intermediatesupporting elements 67, which are still below the separator 60, arelocated in one plane. As soon as the separator 60, in the course of itssteady downwards motion, reaches the region of action of theintermediate supporting elements 67, the outer supporting ring 86 onceagain commences a synchronous downwards motion, so that the intermediatesupporting elements 67 can be introduced into the holding pockets 66 ofthe separator 60, without there being any relative axial movementbetween the parts.

As soon as the intermediate supporting elements 67 engage the separator60, they take over the supporting of the separator 60 and, with that,the supporting of the molded object R resting on it, insofar as thisobject has already been formed. This makes it possible to move thelifting table 23 and the supporting panel 15 resting on this tabledownward at an increased rate with the consequence that the spacer 98 isfreed from supporting contact with the underside of the separator 60 andthat the discharging equipment 92 can commence its activity as soon asthe lifting table 23 has reached its lower end position. For taking outthe molded object R, the lifting table 23 with the spacer 98 is first ofall lifted once again by a short distance, the suction grippers 93, 94are brought into engagement and the fastening jaws 90 are loosened,after which the lifting table 23 once again is moved down into its lowerend position. By these means, the spacer 98 is held by the suctiongrippers 93, 94 so that it can move freely and can be moved out of themolding equipment 1 with the help of the frame 96.

As soon as the spacer 98 is removed, the lifting table 23 is moved uponce again to contact the separator 60. As soon as this contact is made,the upwards movement is converted into downward motion, which issynchronous with the intermediate supporting elements and for which thesupporting panel 15 once again can assume the function of supporting theseparator 60 and the molded body R above the separator 60. As soon asthe fastening jaws 90 have secured the lower end of the molded object Rand of the separator 60 on the supporting panel 15, the intermediatesupporting elements 67 are moved back into their neutral position,whereupon the outer supporting ring 86 is returned into its upper endposition.

As soon as the molded body R, which is being formed, has reached itsspecified length, which can be determined by measuring the path,determining the weight or in some other suitable manner (photoelectricbarrier), the supply of mineral material composition is switched off anda separator 60 is deposited on the upper end of the column of material.After being introduced into the molding space 6, this separator 60settles under gravity on the upper end of the column of material or canalso be placed with the help of pressure elements on the upper end ofthe column of material. As soon as the new separator 60 is resting onthe upper end of the column of material, the supply of mineral castingcomposition is continued once again and initially carried out on agreater scale, so that shortly, despite the further downward motion ofthe previously formed molded body R, the column of material of themolded object R, which is to be formed next, once again attains thespecified nominal height in the molding space 6. After that, themanufacturing process is continued in the manner already described;after the film curtains 33, 34 are severed and the finished moldedobject R, which has been removed from the molding space 6, is detachedfrom the separator 66 above this molded body R, the latter is removedfrom the molding equipment 1 with the help of the discharging equipment92 as described previously with respect to the spacer 98. The positionof the molded body R, which is raised once again at the time, at whichthe molded body R is removed by the discharging equipment 92, isillustrated in FIG. 18 by phantom lines. At the same time, FIG. 11illustrates by a phantom line the upper end of the molded object R,moved by the accelerated lowering of the lifting table 23 out of contactwith the separator 60 above.

The pipes, produced with the second embodiment of the molding equipment1, can be used as propulsion pipes or, if formed with spigots at bothends, can be assembled with the help of double sockets into a pipeline.They can, however, also be used as molded blanks for further conversionin a treatment station, in which the ends of the pipes are finished, forexample, by machining.

Preferably and pursuant to the invention, molded objects, producedaccording to the inventive method and with the second embodiment of themolding equipment 1, are used as the main tubular component for theformation of a socket pipe, which consists of this main part and aseparately constructed socket part, which surrounds the end of the mainpart with a connecting region, both parts being connected without ajoint in the region of mutually facing surfaces.

FIGS. 20 to 22 show different embodiments of such polymer concretesocket pipes, which are assembled pursuant to the invention, intruncated half sections. For examples, FIG. 20 shows a main part 100 inthe region of an end, which is unchanged in cross section and engages aseparately produced socket part 101, which surrounds with a connectingregion 102 the end of the main part 100. At the same time, the socketpart 101 has a peripheral ring land 103, which protrudes radiallyinwards and the internal diameter of which is identical with theinternal diameter of the main part 100. The socket part 101 isdimensioned so that a gap region 104 remains between the mutuallyopposite surfaces of the main part 100 and of the socket part 101. Thegap region 104 is filled with a polymer casting composition as adhesive,which is identical or at least compatible with the polymer component ofthe polymer concrete and forms an intimate connection.

For the embodiment of the socket pipe of FIG. 21, the socket part 101′is joined to the end of the main part 100 by casting, a solid,joint-free connection also being formed. To increase the strength of thejoint, the socket end of the main part 100 can be provided at theoutside with a recess 105 which, if necessary, can also be provided forthe embodiment of the socket pipe of FIG. 20.

FIG. 22 illustrates an embodiment, for which both ends are constructedas a type of spigot with a recess 105 and 106. In the case of theexample shown, the recess serves to accommodate a seal 107. The socketpart 101″ is shaped particularly simply and can be glued by means of apolymeric compound casting composition in the gap 104′ to the socket endof the main part 100. For increasing the strength of the connection, thesocket part 101″ can also be provided on the inside, in the connectingregion 102, with an appropriate recess, which may also be provided inthe connecting region 102 of the embodiment of FIG. 20. A polymerconcrete composition, which has a slump test value that permits a flowinto the joint gap regions 104, 104′ can also be used as polymericcasting composition.

What is claimed is:
 1. A method for the production of tubular productsfrom a molding material in which said molding material is introducedinto a molding space between a mold core and a mold casing whichsurrounds said mold core and said molding material is supported on aclosing part disposed below said mold core and said mold casing, whereinsaid mold core and mold casing have a longitudinal central axis which isvertically disposed, comprising the steps of: providing a mold core anda mold casing along with a molding space between said mold core and amold casing; providing said mold core and said mold casing each with anaxial length which is less than the length of the tubular product to beproduced; introducing said molding material from above said moldingspace into said molding space to form a column of molding material insaid molding space; shaking said molding material which has beenintroduced into said molding space; heating said molding material whichhas been introduced into said molding space; commencing curing of saidmolding material in a lower region of said molding space; dischargingsaid molding material which has commenced curing from said lower regionof said molding space in the form of a discharging column of solidifiedmolding material; lowering said discharging column of solidified moldingmaterial by lowering said closing part relative to said mold core andsaid mold casing; passing additional molding material from above saidmolding space into said molding space; simultaneously performing saidpassing step and said discharging step; shaking said additional moldingmaterial in said molding space; heating said additional molding materialin said molding space; and continuing lowering of said column of moldingmaterial until said column of molding material is at a heightcorresponding to a desired longitudinal length of the molded productwhich is greater than the axial length of Said mold core and said moldcasing.
 2. A method according to claim 1 wherein said passing stepcomprises passing said molding material into said molding space at asubstantially constant rate.
 3. A method according to claim 1, whereinsaid introducing step comprises introducing said molding material intosaid molding space to a nominal height, said passing step comprisingpassing said additional molding material into said molding space untilsaid molding material is at a height corresponding to a longitudinallength of said molded product.
 4. A method according to claim 1 whereinsaid introducing step comprises filling a lower part of the moldingspace with said molding material.
 5. A method according to claim 1further comprising effecting at least one of said shaking and heatingsteps in respective zones disposed in an axially superimposedrelationship on said mold core, disposing said mold core in a lowerinitial position in which a lower end of said zones is adjacent to alower end of said molding space, and moving said mold core upwardlyrelative to said mold casing to an upper position in which an upper endof the zones is adjacent to an upper end of said molding space.
 6. Amethod according to claim 1 further comprising effecting at least one ofsaid shaking and heating steps in respective zones disposed in axiallysuperimposed relationship on said mold core, wherein said zones extendsubstantially over the height of said molding space, and furthercomprising activating and deactivating said at least one of said shakingand heating steps in said zones.
 7. A method according to claim 1wherein said closing part forms the lower end of said molding space inan initial position, and wherein, after said curing step has commencedin said molding material in said lower region of said molding spacewhich is disposed adjacent to said closing part, lowering said closingpart and said column of solidified molding material parallel to saidcentral axis a distance which enables producing a molded product of adesired longitudinal length.
 8. A method according to claim 1 whereinprior to said step of introducing said molding material into saidmolding space, disposing a separator in the upper region of the moldingspace such that said separator supports the column of molding materialintroduced into said molding space during said introducing step,lowering said separator and said column of molding material into a lowerregion of the molding space, said shaking step comprising shaking saidmolding material which is supported by said separator, said heating stepcomprising heating said column of molding material in said lower regionof said molding space and thereby commencing curing of said moldingmaterial adjacent to said separator, and lowering said separator alongwith said column of molding material parallel to said central axis adistance which enables producing a molded product of a desiredlongitudinal length.
 9. A method according to claim 1 further comprisingrotating said mold casing and said mold core about said central axiswhile introducing said molding material into said molding space.
 10. Amethod according to claim 1 wherein said heating step includes heatingsaid molding material using electromagnetic microwaves.
 11. A methodaccording to claim 1 wherein said molding material commences its initialcuring process within a temperature range of 50 to 90 degrees Celsius.12. A method according to claim 1 further comprising separating saidmolding material from said mold casing and said mold core utilizing aseparating means.
 13. A method according to claim 12 wherein said stepof separating said molding material from said mold casing and said moldcore includes providing sheets of film formed into a curtain along theoutside surface of said core mold and along thee inside surface of saidmold casing.
 14. A method for the production of tubular products from amolding material in which said molding material is introduced into amolding space between a mold core and said molding material is supportedon a closing part disposed below said mold core and said mold casing, amold casing which surrounds said mold core and wherein said mold coreand mold casing have a longitudinal central axis which is verticallydisposed, comprising the steps of: providing a mold core and a moldcasing each with an axial length which is less than the length of thetubular product to be molded; introducing said molding material fromabove said molding space into an upper region of said molding space toform a column of molding material in said molding space; effectingsolidification of said molding material in a lower region of saidmolding space; discharging said solidified molding material from saidlower region of said molding space in the form of a dischargingsolidified column of molding material; lowering said discharging columnof solidified molding material by lowering said dosing part relative tosaid mold core and said mold casing; passing additional molding materialfrom above said molding space into said upper region of said moldingspace to continue forming of said column of molding material in saidmolding space; continuing to effect solidification of said moldingmaterial in said lower region of said molding space; and continuing saiddischarging step and said lowering step until said column of moldingmaterial is at a height corresponding to a desired longitudinal lengthof the molded product which is greater than the axial length of saidmold core and said mold casing.
 15. Apparatus for producing tubularmolded products from molding material comprising: a mold casing and amold core having a common longitudinal central axis which is verticallydisposed, said mold casing and mold core being spaced from one anotherto define a molding space therebetween: a closing part for supportingsaid molding material disposed below said mold core and said moldcasing; a supply mechanism for supplying said molding material fromabove said molding space into said molding space; a treatment mechanismdisposed at treatment zones on said mold core for treating said moldingmaterial in said molding space along treatment zones, said treatmentmechanism being selected from the group consisting of treating saidmolding material by shaking said molding material and treating saidmolding material by heating said molding material; said mold casing andsaid mold core each having an axial length which is less than an axiallength of the molded product to be produced such that said supplymechanism operates to supply said molding material from above saidmolding space into said molding space while a column of solidifiedmolding material discharges from a bottom region of said mold casing;and an operable mechanism for lowering a lower end of the column ofmolding material in a direction parallel to said central axis bylowering said closing part relative to said mold core and said moldcasing, said operable mechanism lowering the lower end of the column ofmolding material from an initial position to a lowered position whichenables production of a molded product of a desired longitudinal lengthgreater than the longitudinal length of said mold casing and said moldcore.
 16. Apparatus according to claim 15 wherein said treatment zonesare disposed in axially limited sections on said mold core, and ashifting device for axially shifting said mold core relative to saidmold casing to thereby axially shift said treatment zones.
 17. Apparatusaccording to claim 15 further comprising shifting device operable tomove said treatment mechanism laterally relative to said mold casing.18. Apparatus according to claim 15 wherein said mold casing defines theouter boundary of a tubular molded product having a coupling. 19.Apparatus according to claim 15 further comprising a rotatable mechanismfor rotating said mold casing about a rotatable axis which is coincidentwith said central axis, said supply mechanism having a stationarydischarge portion which discharges said casting material into saidmolding space.
 20. Apparatus according to claim 15 wherein said moldcore includes a central guiding part and a mounting device slidablyreceiving said central guiding part for guiding axial movement of saidmold core along said central axis.
 21. Apparatus according to claim 15wherein said closing part closing off the bottom of said molding spacein said initial position, said closing part including an inner moldportion formed into a plurality of mold segments disposed concentricallyto said central axis, and an actuating mechanism for moving said moldsegments in a radial direction between an operational position and ademolding position.
 22. Apparatus according to claim 15 wherein saidtreatment mechanism comprises a heater on said mold core for heatingsaid molding material in said molding space.
 23. Apparatus according toclaim 15 wherein said treatment mechanism comprises a heater on saidmold core and further comprising a heating device on said mold casingfor heating said molding material in said molding space.
 24. Apparatusaccording to claim 15 further comprising jaw means overlying saidclosing part and movable between a non-engaged and an engaged position,said jaw means engaging said molded product on said closing part when insaid engaged position, said jaw means being disengaged from said moldedproduct on said closing part when in said disengaged position. 25.Apparatus according to claim 15 wherein said closing part closes off alower end of said molding space in said initial position, and drivemeans for synchronously and alternatively rotating said mold core, saidmold casing, and said dosing part.
 26. Apparatus according to claim 25wherein said drive means alternatively rotates said mold core, said moldcasing and said closing part about 300 degrees.
 27. Apparatus accordingto claim 15 comprising a heater on said mold casing for heating saidmolding material in said molding space.
 28. Apparatus according to claim27 wherein said heater comprises a microwave generator.
 29. Apparatusaccording to claim 15 further comprising a film supply mechanism forsupplying a film lining to said molding space on an outside of said moldcore and an inside of said mold casing.
 30. Apparatus according to claim29 wherein said film supply mechanism include film supply rolls, acarrying frame mounted on said mold core, said film supply rolls beingmounted on said carrying frame.
 31. Apparatus according to claim 29wherein said film supply mechanism includes film supply rolls, acarrying frame mounted on an upper part of said mold casing, said filmsupply rolls being mounted on said carrying frame.
 32. Apparatusaccording to claim 29 wherein said mold casing comprising an upper moldcasing part and a lower mold casing part, said upper mold casing parthaving an inner wall having a lower edge area, said lower mold casingpart having an upper edge area, said mold core having an outer wallhaving a lower edge area, said closing part having an inner mold parthaving a facing area facing said lower edge area of said mold core, andsuction means at each of said respective areas for holding said film ateach of said respective areas.
 33. Apparatus according to claim 15further comprising a separator for supporting a lower end of said columnof molding material.
 34. Apparatus according to claim 33 wherein saidseparator is in the form of an annular ring which has an upper partwhich forms one end of a finished molded product into a configurationcorresponding to the configuration of said upper part of said annularring.
 35. Apparatus according to claim 33 wherein said separator haspockets which open radially outwardly, and supporting elements operableto be inserted into said pockets.
 36. Apparatus according to claim 33wherein said separator is in the form of a ring which is divided into aplurality of segments along generally vertical planes.
 37. Apparatusaccording to claim 33 wherein said separator comprises a plasticmaterial, said separator having an upper side and an underside providedwith vent openings, said separator having outer border edges withsealing lips.
 38. Apparatus according to claim 15 further comprisingdischarging equipment including a gripper means operable to grip theoutside of a finished molded product on said closing part and todisplace said finished molded product in a horizontal direction. 39.Apparatus according to claim 38 wherein said gripper means includes afirst pair of suction grippers disposed one above the other and, asecond pair of suction grippers disposed one above the other, said firstpair of suction grippers being diametrically opposed to said second pairof suction grippers, and an actuating mechanism for moving said firstand second pairs of suction grippers radially between an engagedposition and a disengaged position, said first and second pairs ofsuction grippers engaging said finished molded product on said closingpart when in said engaged position, said first and second pairs ofsuction grippers being disengaged from said finished molded product onsaid closing part when in said disengaged position, and a vacuummechanism for supplying a vacuum to said first and second pairs ofsuction grippers when said first and second pairs of suction grippersare in said engaged position.
 40. Apparatus according to claim 39wherein said discharging equipment further comprises a frame forsupporting said actuating mechanism and said suction grippers, andhorizontal guides along which said frame is movable horizontally from atake-over position to a delivery position.
 41. Apparatus for producingtubular molded products from molding material comprising: a mold casingand a mold core having a common longitudinal central axis which isvertically disposed, said mold casing and mold core being spaced fromone another to define a molding space therebetween; a supply mechanismfor supplying said molding material from above said molding space intosaid molding space; a treatment mechanism disposed at treatment zones onsaid mold core for treating said molding material in said molding spacealong treatment zones said treatment mechanism being selected from thegroup consisting of treating said molding material by shaking saidmolding material and treating said molding material by heating saidmolding material; said mold casing having an axial length which is lessthan an axial length of the molded product to be produced such that saidsupply mechanism operates to supply said molding material from abovesaid molding space into said molding space while a column of solidifiedmolding material discharges from a bottom region of said mold casing; anoperable mechanism for lowering a lower end of the column of moldingmaterial in a direction parallel to said central axis from an initialposition to a lowered position which enables production of a moldedproduct of a desired longitudinal length; a separator for supporting thelower end of said column of molding material; and a film supplymechanism for supplying a film lining to said molding space on theoutside of said mold core and on the inside of said mold casing, saidseparator having an inside with an indentation and an outside with anindentation, and a severing mechanism for severing said film, saidsevering mechanism being operable to extend into said indentations. 42.Apparatus for producing tubular molded products from molding materialcomprising: a mold casing and a mold core having a common longitudinalcentral axis which is vertically disposed, said mold casing and moldcore being spaced from one another to define a molding spacetherebetween; a supply mechanism for supplying said molding materialfrom above said molding space into said molding space; a treatmentmechanism disposed at treatment zones on said mold core for treatingsaid molding material in said molding space along treatment zones saidtreatment mechanism being selected from the group consisting of treatingsaid molding material by shaking said molding material and treating saidmolding material by heating said molding material; said mold casinghaving an axial length which is less than an axial length of the moldedproduct to be produced such that said supply mechanism operates tosupply said molding material from above said molding space into saidmolding space while a column of solidified molding material dischargesfrom a bottom region of said mold casing; an operable mechanism forlowering a lower end of the column of molding material in a directionparallel to said central axis from an initial position to a loweredposition which enables production of a molded product of a desiredlongitudinal length; said mold casing being divided into two halfsections by an axial plane which is parallel to said central axis andwhich includes said central axis; actuators for moving said two halfsections in a direction perpendicular to said central axis between aclosed position and an open position and a film supply mechanism forsupplying a film to said molding space on an outside of said mold coreand on an inside of said mold casing, a film severing device forsevering the film below an upper part of said mold casing and below saidmold core, said severing device including inner and outer severingknives for severing said film on said outside of said mold core and onsaid inside of said mold casing along a common horizontal plane. 43.Apparatus according to claim 42 wherein each of said inner and outersevering knives include a driving mechanism for moving each of saidinner and outer severing knives in a generally radial direction betweena non-cutting position an a cutting position, said severing deviceincluding a mounting device mounting said cutting knives for at leastpartial rotary movement about said central axis.
 44. Apparatus accordingto claim 43 wherein said mounting device mounts said cutting knives ofsaid inner severing device to an underside of said mold core. 45.Apparatus according to claim 43 further comprising a fixed moldstructure, said mounting device mounting said cutting knives of saidsevering device on an outer support ring which is suspended from saidfixed mold structure.
 46. Apparatus according to claim 45 furthercomprising a separator operable to support said column of moldingmaterial at the bottom of said column of molding material, saidseparator having pockets which open radially outwardly, a holdingmechanism which includes holding elements and actuators for moving saidholding elements radially between non-inserted and inserted positions,said holding elements being disposed in said pockets of said separatorswhen said holding elements are in said inserted position, said holdingelements being removed from said pockets of said separators when saidholding elements are in said non-inserted position, said actuators andholding elements being carried by said support ring.
 47. Apparatusaccording to claim 46 further comprising guides for guiding said supportring for movement parallel to said central axis, and a driving mechanismon said fixed mold structure for moving said support ring along saidguides between an upper end position and a lower end position. 48.Apparatus for producing tubular molded products from molding materialcomprising: a mold casing and a mold core having a common longitudinalcentral axis which is vertically disposed, said mold casing and moldcore being spaced from one another to define a molding spacetherebetween; a supply mechanism for supplying said molding materialfrom above said molding space into said molding space; said mold casingbeing divided into an upper mold casing part and a lower mold casingpart by a plane disposed perpendicular to said central axis, said upperand lower mold casing parts being juxtaposed to one another in an upperstart position; said lower mold casing part being divided into two halfsections by an axial plane which is parallel to said central axis andwhich includes said central axis, actuators for moving said two halfsections in a direction perpendicular to said central axis between aclosed position and an open position; an operating mechanism forlowering said lower mold casing part from said start position to a lowerposition where said upper and lower mold casing parts are spaced fromone another; a treatment mechanism for treating said molding material insaid molding space, said treatment mechanism being selected from thegroup consisting of shaking said molding material and heating saidmolding material, said treatment mechanism being operable to effectsolidification of the molding material in said lower mold casing partand in a lower region of said upper mold casing part; said upper moldcasing part and said mold core each having an axial length which is lessthan an axial length of the molded product to be produced; said operablemechanism lowering said lower mold casing part from said start positionto said lower position as said solidified molding material in said lowerregion of said upper mold casing part discharges from said lower regionof said upper mold casing part to thereby enable production of asolidified molded product of a desired longitudinal length; and a filmsupply mechanism for supplying a film to said molding space on anoutside of said mold core and on an inside of said mold casing, a filmsevering device for severing the film below an upper part of said moldcasing and below said mold core said severing device including inner andouter severing knives for severing said film on said outside of saidmold core and on said inside of said mold casing along a commonhorizontal plane.
 49. Apparatus for producing tubular molded productsfrom molding material comprising: a mold casing and a mold core having acommon longitudinal central axis which is vertically disposed, said moldcasing and mold core being spaced from one another to define a moldingspace therebetween; a support member for supporting said moldingmaterial disposed below said mold core and said mold casing; a supplymechanism for supplying said molding material from above said moldingspace into said molding space; said mold casing having an upper moldcasing part and a lower mold casing part, said upper and lower moldcasing parts being juxtaposed to one another in an upper start position;an operating mechanism for lowering said lower mold casing part and saidsupport member relative to said upper mold casing part and said moldcore from said start position to a lower position where said upper andlower mold casing parts are spaced from one another; a treatmentmechanism for treating said molding material in said molding space, saidtreatment mechanism being selected from the group consisting of shakingsaid molding material and heating said molding material, said treatmentmechanism being operable to effect solidification of the moldingmaterial in said lower mold casing part and in a lower region of saidupper mold casing part; said upper mold casing part and said mold coreeach having an axial length which is less than an axial length of themolded product to be produced; said operable mechanism lowering saidlower mold casing part and said support member from said start positionto said lower position as said solidified molding material in said lowerregion of said upper mold casing part discharges from said lower regionof said upper mold casing part to thereby enable production of asolidified molded product of a desired longitudinal length greater thanthe longitudinal length of said upper mold casing part and said moldcore.
 50. Apparatus according to claim 49 wherein said lower mold casingis divided into two half sections by an axial plane which is parallel tosaid central axis and which includes said central axis, and actuatorsfor moving said two half sections in a direction perpendicular to saidcentral axis between a closed position and an open position. 51.Apparatus according to claim 50 wherein said upper mold casing part issupported on a mounting device, and a rotary mechanism rotatablysupporting said mounting device for effecting rotary movement of saidupper mold casing part about said central axis.
 52. Apparatus accordingto claim 50, further comprising a film supply mechanism for supplying afilm to said molding space on an outside of said mold core and on aninside of said upper and lower mold casing parts, severing means forsevering said film along a cutting plane extending transversely to saidcentral axis, said cutting plane being disposed in spaced relationshipbelow an underside of said upper mold casing part and above an upper endof a finished molded object.
 53. Apparatus according to claim 50 whereinsaid support member further supports said lower mold casing part. 54.Apparatus according to claim 53 wherein said actuators move said twohalf sections into said open position when said lower mold casing partis in its lower position, said operating mechanism being operable toraise said support member and said lower mold casing part from saidlower position to an intermediate position while said two half sectionsare in said open position, said intermediate position being at a samelevel as said start position.
 55. Apparatus according to claim 53wherein said operable mechanism further comprises a lifting table onwhich said support member is supported, vertical guides guiding saidlifting table for vertical movement, and a mounting device for mountingsaid support table on said lifting table for rotatable movement aboutsaid central axis.